Time to backwash and sand in filter basket?

[pypeke]

My new, Glycerin filled gauge is installed, so I think I am supposed to backwash when the pressure reading gets 25% higher. Am I correct?

Question 1. Do I start reading from the 0? That is what makes sense to me, but there are only 4 "marks" between 0 and 5. If I start counting from the 0, the pressure is not quite 2 1/2. If I start at the 5 and count backwards, the pressure is not quite 3 1/2.

2.5 - 25% = 1.875 so I would backwash at 4.375 or round up to 4 1/2.
3.5 - 25% = 2.625 so I would backwash at 6.125 or round up to 6 1/2.

With such low pressure numbers, is it more important or less important that I get the backwash number exactly right?

Can I just backwash at 5 1/2 or will that be too soon?




Question 2: I am not sticking my hand in there, but could the brown stuff be sand or is it organic waste? Can sand float up enough to get into the skimmer hair net?



Thanks for any opinions.

 

[jblizzle]

You should do the pressure checks to determine filter cleaning at a higher RPM so you can actually see the pressure change.

Sand would not be in your skimmer. Likely it is pollen.

 

[pypeke]

I didn't think the sand could float up into the skimmer, but thought I might be wrong.

Thanks. The gauge is 0 at 1500 rpm, 3.5 at 2000 rpm, and 5 at 2500 rpm.

Why does the gauge only have 4 marks instead of 5 from 0 to 5?

 

[jblizzle]

Because difficult to differentiate those low pressures I guess. Do your pressure checks at an even higher speed so you better know when to clean the filter

 

[pypeke]

Oh, jeez, that was such a duh! or senior moment for me.....well, longer than a moment.

Can't believe I didn't think of raising the rpm to check.

I am also getting sand in the little clear plastic bubble on the filter. We put new laterals in the filter this year, and were very careful when adding the sand back in.